The principal objective of the Cell Culture Core Laboratory is to maintain a sufficient supply of cultured cells for the various studies that are proposed in the individual projects of this Program Project application and to provide this service with the highest level of quality control. In addition, the Core will continue to function as an educational facility in training members of the Program Project laboratories in proper cell culture methods and quality control. During the previous funding period this core laboratory has met its objective with respect to providing program investigators with sufficient numbers of characterized cultured cells for their studies. The great majority of the published reports from the program project contain experiments that were dependent on the proper operation of this core laboratory. Dozens of individuals from the project laboratories have been trained in cell culture methods and the facility has been used for cell culture studies performed by individuals in the laboratories of Project Leaders when their own lab facilities were occupied. Although all Project Leaders maintain satellite cell culture facilities, these investigators have been fully dependent on the core laboratory for stock flasks of cells. Core laboratory personnel have established countless long-term cultures of bovine aortic endothelial cells (EC), human umbilical vein EC, mouse aortic EC, and human foreskin fibroblasts. Many established cell lines have also been provided on a regular basis. Quality control in the facility has been excellent with minimal incidents of microbiologic contamination over the years in spite of the many individuals sharing the facility. This success reflects the fact that those using the facility are required to go through the most rigorous of mammalian cell culture training. This training will continue to be provided to all Program Project scientists performing cell culture experiments.